In the manufacture of electronic devices, a substrate such as a semiconductor wafer, a glass plate, or a polymer, etc. typically undergoes a sequence of manufacturing or processing steps. These steps may include, for example, polishing, thin film deposition, oxidation or nitration, cleaning, etching, photolithography, and heat treatment, etc. Between processing stations, a substrate may be carried within a substrate carrier. For example, FIG. 1 is a perspective view of a substrate 100 that may be carried within a substrate carrier 102 (e.g., a multi-slot substrate carrier). During the manufacture of such electronic devices, substrate 100 may be transported from the substrate carrier 102 to a substrate support at a processing station (not shown), and after processing is completed within a particular processing station, the substrate 100 may be moved from the processing station back into the same or a different substrate carrier 102. The substrate 100 in the substrate carrier 102 may then be transported to another processing station where additional processing steps may take place on the substrate 100.
During transport of the substrate 100 to the substrate support of the processing station (not shown), and also during return transport of the substrate 100 from the substrate support back to the substrate carrier 102, for example, a robot arm or other automated substrate carrying assembly 103 (FIG. 2), with an attached end effector 104 may carry the substrate 100. For example, during the movement to the processing station, the end effector 104 and substrate 100 may be transported to a location slightly above the substrate support and then lowered to place the substrate 100 onto the substrate support. After the placement of the substrate 100, the end effector 104 may be retracted, and another substrate may be retrieved and placed onto another substrate support, for example. Following completion of processing step(s) at the processing station, the substrate may then be transported to, and placed to rest in, a slotted substrate support of a carrier, such as in the multi-slot carrier 102. Each of these placement operations whereby the substrate 100 is placed onto the substrate support of the processing station or onto the slotted substrate support of a carrier 102, is referred to herein as a “put.”
Methods and apparatus for facilitating such puts are desired.